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2017-06-30kbuild: thin archives use P option to arNicholas Piggin
The P option makes ar do full path name matching and can prevent ar from discarding files with duplicate names in some cases of creating thin archives from thin archives. The sh architecture in particular loses some object files from its kernel/cpu/sh*/ directories without this option. This could be a bug in binutils ar, but the P option should not cause any negative effects so it is safe to use to work around this with. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-05-03objtool: make it visible in make V=1 outputJiri Slaby
It is currently impossible to see what is going on with objtool when building, so call echo-cmd to see the actions: gcc -Wp,-MD,arch/x86/entry/.entry_64.o.d -nostdinc -isystem ... ./tools/objtool/objtool check "arch/x86/entry/entry_64.o"; Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Michal Marek <mmarek@suse.com> Cc: linux-kbuild@vger.kernel.org Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-04-25kbuild: Add support to generate LLVM assembly filesVinícius Tinti
Add rules to kbuild in order to generate LLVM assembly files with the .ll extension when using clang. # from c code make CC=clang kernel/pid.ll Signed-off-by: Vinícius Tinti <viniciustinti@gmail.com> Signed-off-by: Behan Webster <behanw@converseincode.com> Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-02-03kbuild: modversions: add infrastructure for emitting relative CRCsArd Biesheuvel
This add the kbuild infrastructure that will allow architectures to emit vmlinux symbol CRCs as 32-bit offsets to another location in the kernel where the actual value is stored. This works around problems with CRCs being mistaken for relocatable symbols on kernels that self relocate at runtime (i.e., powerpc with CONFIG_RELOCATABLE=y) For the kbuild side of things, this comes down to the following: - introducing a Kconfig symbol MODULE_REL_CRCS - adding a -R switch to genksyms to instruct it to emit the CRC symbols as references into the .rodata section - making modpost distinguish such references from absolute CRC symbols by the section index (SHN_ABS) - making kallsyms disregard non-absolute symbols with a __crc_ prefix Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-17Merge branch 'kbuild' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull kbuild updates from Michal Marek: - prototypes for x86 asm-exported symbols (Adam Borowski) and a warning about missing CRCs (Nick Piggin) - asm-exports fix for LTO (Nicolas Pitre) - thin archives improvements (Nick Piggin) - linker script fix for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION (Nick Piggin) - genksyms support for __builtin_va_list keyword - misc minor fixes * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: x86/kbuild: enable modversions for symbols exported from asm kbuild: fix scripts/adjust_autoksyms.sh* for the no modules case scripts/kallsyms: remove last remnants of --page-offset option make use of make variable CURDIR instead of calling pwd kbuild: cmd_export_list: tighten the sed script kbuild: minor improvement for thin archives build kbuild: modpost warn if export version crc is missing kbuild: keep data tables through dead code elimination kbuild: improve linker compatibility with lib-ksyms.o build genksyms: Regenerate parser kbuild/genksyms: handle va_list type kbuild: thin archives for multi-y targets kbuild: kallsyms allow 3-pass generation if symbols size has changed
2016-12-11kbuild: cmd_export_list: tighten the sed scriptNicolas Pitre
When LTO is used, some ___ksymtab_string sections are seen by this sed script, creating lines containing a single ) such as: EXPORT(foo) ) ) EXPORT(bar) Let's make it so the + character is also required for any line to be printed. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-29kbuild: improve linker compatibility with lib-ksyms.o buildNicholas Piggin
lib-ksyms.o is created by linking an empty input file with a linker script containing the interesting bits. Currently the empty input file is an archive containing nothing, however this causes the gold linker to segfault. I have opened a bug against gold https://sourceware.org/bugzilla/show_bug.cgi?id=20767 However this can be worked around by assembling an empty file to link with instead. The resulting lib-ksyms.o is slightly larger (seemingly due to empty .text, .data, .bss setions added), but final linked output should not be changed. Reported-by: Anton Blanchard <anton@samba.org> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-29kbuild: thin archives for multi-y targetsNicholas Piggin
THIN_ARCHIVES builds archives for built-in.o targets, have it build multi-y targets as archives as well. This saves another ~15% of the size of intermediate artifacts in the build tree. After this patch, the linker is only used in final link, and special cases like vdsos. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-09kbuild: be more careful about matching preprocessed asm ___EXPORT_SYMBOLNicholas Piggin
The CRC code for asm exports grabs the preprocessed asm, finds the ___EXPORT_SYMBOL and turns those into EXPORT_SYMBOL in a C program that can be preprocessed and parsed to create the CRC signatures from the type. The existing regex matching and replacement is too strict, and doesn't deal well with whitespace among other things. The line " EXPORT_SYMBOL(sym)" in a .S file would not match due to initial whitespace, for example, which resulted in x86's ___preempt_schedule failing to get CRCs. Reported-by: Philip Müller <philm@manjaro.org> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-11-01kbuild: modversions for EXPORT_SYMBOL() for asmNicholas Piggin
Allow architectures to create asm/asm-prototypes.h file that provides C prototypes for exported asm functions, which enables proper CRC versions to be generated for them. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-10-22kbuild: prevent lib-ksyms.o rebuildsNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reported-by: Russell King <rmk+kernel@armlinux.org.uk> Tested-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-09-09kbuild: allow architectures to use thin archives instead of ld -rStephen Rothwell
ld -r is an incremental link used to create built-in.o files in build subdirectories. It produces relocatable object files containing all its input files, and these are are then pulled together and relocated in the final link. Aside from the bloat, this constrains the final link relocations, which has bitten large powerpc builds with unresolvable relocations in the final link. Alan Modra has recommended the kernel use thin archives for linking. This is an alternative and means that the linker has more information available to it when it links the kernel. This patch enables a config option architectures can select, which causes all built-in.o files to be built as thin archives. built-in.o files in subdirectories do not get symbol table or index attached, which improves speed and size. The final link pass creates a built-in.o archive in the root output directory which includes the symbol table and index. The linker then uses takes this file to link. The --whole-archive linker option is required, because the linker now has visibility to every individual object file, and it will otherwise just completely avoid including those without external references (consider a file with EXPORT_SYMBOL or initcall or hardware exceptions as its only entry points). The traditional built works "by luck" as built-in.o files are large enough that they're going to get external references. However this optimisation is unpredictable for the kernel (due to above external references), ineffective at culling unused, and costly because the .o files have to be searched for references. Superior alternatives for link-time culling should be used instead. Build characteristics for inclink vs thinarc, on a small powerpc64le pseries VM with a modest .config: inclink thinarc sizes vmlinux 15 618 680 15 625 028 sum of all built-in.o 56 091 808 1 054 334 sum excluding root built-in.o 151 430 find -name built-in.o | xargs rm ; time make vmlinux real 22.772s 21.143s user 13.280s 13.430s sys 4.310s 2.750s - Final kernel pulled in only about 6K more, which shows how ineffective the object file culling is. - Build performance looks improved due to less pagecache activity. On IO constrained systems it could be a bigger win. - Build size saving is significant. Side note, the toochain understands archives, so there's some tricks, $ ar t built-in.o # list all files you linked with $ size built-in.o # and their sizes $ objdump -d built-in.o # disassembly (unrelocated) with filenames Implementation by sfr, minor tweaks by npiggin. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-08-07[kbuild] handle exports in lib-y objects reliablyAl Viro
Collect the symbols exported by anything that goes into lib.a and add an empty object (lib-exports.o) with explicit undefs for each of those to obj-y. That allows to relax the rules regarding the use of exports in lib-* objects - right now an object with export can be in lib-* only if we are guaranteed that there always will be users in built-in parts of the tree, otherwise it needs to be in obj-*. As the result, we have an unholy mix of lib- and obj- in lib/Makefile and (especially) in arch/*/lib/Makefile. Moreover, a change in generic part of the kernel can lead to mysteriously missing exports on some configs. With this change we don't have to worry about that anymore. One side effect is that built-in.o now pulls everything with exports from the corresponding lib.a (if such exists). That's exactly what we want for linking vmlinux and fortunately it's almost the only thing built-in.o is used in. arch/ia64/hp/sim/boot/bootloader is the only exception and it's easy to get rid of now - just turn everything in arch/ia64/lib into lib-* and don't bother with arch/ia64/lib/built-in.o anymore. [AV: stylistic fix from Michal folded in] Acked-by: Michal Marek <mmarek@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-07Shared library supportEmese Revfy
Infrastructure for building independent shared library targets. Based on work created by the PaX Team. Signed-off-by: Emese Revfy <re.emese@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-04-20kbuild: rename cmd_as_s_S to cmd_cpp_s_SMasahiro Yamada
This command just preprocesses .S files into .s files, so cmd_cpp_s_S seems more suitable. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-04-20kbuild: rename cmd_cc_i_c to cmd_cpp_i_cMasahiro Yamada
This command just preprocesses .c files into .i files, so cmd_cpp_i_c seems more suitable. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-03-29kbuild: de-duplicate fixdep usageNicolas Pitre
The generation and postprocessing of automatic dependency rules is duplicated in rule_cc_o_c, rule_as_o_S and if_changed_dep. Since this is not a trivial one-liner action, it is now abstracted under cmd_and_fixdep to simplify things and make future changes in this area easier. In the rule_cc_o_c and rule_as_o_S cases that means the order of some commands has been altered, namely fixdep and related file manipulations are executed earlier, but they didn't depend on those commands that now execute later. Signed-off-by: Nicolas Pitre <nico@linaro.org>
2016-03-29kbuild: record needed exported symbols for modulesNicolas Pitre
Kernel modules are partially linked object files with some undefined symbols that are expected to be matched with EXPORT_SYMBOL() entries from elsewhere. Each .tmp_versions/*.mod file currently contains two line of text separated by a newline character. The first line has the actual module file name while the second line has a list of object files constituting that module. Those files are parsed by modpost (scripts/mod/sumversion.c), scripts/Makefile.modpost, scripts/Makefile.modsign, etc. Only the modpost utility cares about the second line while the others retrieve only the first line. Therefore we can add a third line to record the list of undefined symbols aka required EXPORT_SYMBOL() entries for each module into that file without breaking anything. Like for the second line, symbols are separated by a blank and the list is terminated with a newline character. To avoid needless build overhead, the undefined symbols extraction is performed only when CONFIG_TRIM_UNUSED_KSYMS is selected. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au>
2016-03-05objtool: Detect and warn if libelf is missing and don't break the buildJosh Poimboeuf
With CONFIG_STACK_VALIDATION enabled, if the host system doesn't have a development version of libelf installed, the build fails with errors like: elf.h:22:18: fatal error: gelf.h: No such file or directory compilation terminated. Instead of failing to build, instead just print a warning and disable stack validation. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-next@vger.kernel.org Cc: linux@roeck-us.net Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/8c27fe00face60f42e888ddb3142c97e45223165.1457026550.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29objtool: Add CONFIG_STACK_VALIDATION optionJosh Poimboeuf
Add a CONFIG_STACK_VALIDATION option which will run "objtool check" for each .o file to ensure the validity of its stack metadata. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/92baab69a6bf9bc7043af0bfca9fb964a1d45546.1456719558.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-25kbuild: Allow to specify composite modules with modname-mMichal Marek
This allows to write drm-$(CONFIG_AGP) += drm_agpsupport.o without having to handle CONFIG_AGP=y vs. CONFIG_AGP=m. Only support this syntax for modules, since built-in code depending on something modular cannot work and init/Makefile actually relies on the current semantics. There are a few drivers which adapted to the current semantics out of necessity; these are fixed to also work when the respective subsystem is modular. Acked-by: Peter Chen <peter.chen@freescale.com> [chipidea] Signed-off-by: Michal Marek <mmarek@suse.com>
2015-01-29ftrace: allow architectures to specify ftrace compile optionsHeiko Carstens
If the kernel is compiled with function tracer support the -pg compile option is passed to gcc to generate extra code into the prologue of each function. This patch replaces the "open-coded" -pg compile flag with a CC_FLAGS_FTRACE makefile variable which architectures can override if a different option should be used for code generation. Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-02kbuild: remove obj-n and lib-n handlingMasahiro Yamada
Kconfig never defines CONFIG_* as 'n'. Now obj-n is only used in firmware/Makefile and it can be replaced with obj-. No makefile uses lib-n. Let's rip off obj-n and lib-n. Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Acked-by: Peter Foley <pefoley2@pefoley.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-08-19kbuild: handle multi-objs dependency appropriatelyMasahiro Yamada
The comment in scripts/Makefile.build says as follows: We would rather have a list of rules like foo.o: $(foo-objs) but that's not so easy, so we rather make all composite objects depend on the set of all their parts This commit makes it possible! For example, assume a Makefile like this obj-m = foo.o bar.o foo-objs := foo1.o foo2.o bar-objs := bar1.o bar2.o Without this patch, foo.o depends on all of foo1.o foo2.o bar1.o bar2.o. It looks funny that foo.o is regenerated when bar1.c is updated. Now we can handle the dependency of foo.o and bar.o separately. Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-04-30kbuild: trivial - remove trailing spacesMasahiro Yamada
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-04-16kbuild: move extra gcc checks to scripts/Makefile.extrawarnMasahiro Yamada
W=... provides extra gcc checks. Having such code in scripts/Makefile.build results in the same flags being added to KBUILD_CFLAGS multiple times becuase scripts/Makefile.build is invoked every time Kbuild descends into the subdirectories. Since the top Makefile is already too cluttered, this commit moves all of extra gcc check stuff to a new file scripts/Makefile.extrawarn, which is included from the top Makefile. Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> CC: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-04-09kbuild: LLVMLinux: Adapt warnings for compilation with clangJan-Simon Möller
When compiling kernel with clang, disable warnings which are too noisy, and add the clang flag catch-undefined-behavior. Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de> Signed-off-by: Behan Webster <behanw@converseincode.com> Signed-off-by: Mark Charlebois <mcharleb@gmail.com> Cc: PaX Team <pageexec@freemail.hu>
2014-02-13Kbuild, lto: Disable LTO for asm-offsets.cAndi Kleen
The asm-offset.c technique to fish data out of the assembler file does not work with LTO. Just disable for the asm-offset.c build. Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1391846481-31491-11-git-send-email-ak@linux.intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-03-20genksyms: pass symbol-prefix instead of archJames Hogan
Pass symbol-prefix to genksyms instead of arch, so that the decision what symbol prefix to use is kept in one place. Basically genksyms used to take a -a $ARCH argument and it used that to determine whether to add an underscore symbol prefix. It's now changed to take a -s $SYMBOL_PREFIX argument so that the caller decides whether a symbol prefix is required. The build system then uses CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX to determine whether to pass the argument. Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-08X.509: Add simple ASN.1 grammar compilerDavid Howells
Add a simple ASN.1 grammar compiler. This produces a bytecode output that can be fed to a decoder to inform the decoder how to interpret the ASN.1 stream it is trying to parse. Action functions can be specified in the grammar by interpolating: ({ foo }) after a type, for example: SubjectPublicKeyInfo ::= SEQUENCE { algorithm AlgorithmIdentifier, subjectPublicKey BIT STRING ({ do_key_data }) } The decoder is expected to call these after matching this type and parsing the contents if it is a constructed type. The grammar compiler does not currently support the SET type (though it does support SET OF) as I can't see a good way of tracking which members have been encountered yet without using up extra stack space. Currently, the grammar compiler will fail if more than 256 bytes of bytecode would be produced or more than 256 actions have been specified as it uses 8-bit jump values and action indices to keep space usage down. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-26kbuild: disable -Wmissing-field-initializers for W=1Kirill A. Shutemov
-Wmissing-field-initializers is too noisy to be useful on W=1. Let's move it to W=2. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-08-31scripts/Makefile.build: do not reference EXTRA_CFLAGS as CFLAGS replacementArnaud Lacombe
Usage of these flags has been deprecated for nearly 4 years by: commit f77bf01425b11947eeb3b5b54685212c302741b8 Author: Sam Ravnborg <sam@neptun.(none)> Date: Mon Oct 15 22:25:06 2007 +0200 kbuild: introduce ccflags-y, asflags-y and ldflags-y Moreover, these flags (at least EXTRA_CFLAGS) have been documented for command line use. By default, gmake(1) do not override command line setting, so this is likely to result in build failure or unexpected behavior. Do not advertise for its usage. Cc: Sam Ravnborg <sam@ravnborg.org> Cc: linux-kbuild@vger.kernel.org Signed-off-by: Arnaud Lacombe <lacombar@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-05-24Merge branch 'kbuild' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6: kbuild: make KBUILD_NOCMDDEP=1 handle empty built-in.o scripts/kallsyms.c: fix potential segfault scripts/gen_initramfs_list.sh: Convert to a /bin/sh script kbuild: Fix GNU make v3.80 compatibility kbuild: Fix passing -Wno-* options to gcc 4.4+ kbuild: move scripts/basic/docproc.c to scripts/docproc.c kbuild: Fix Makefile.asm-generic for um kbuild: Allow to combine multiple W= levels kbuild: Disable -Wunused-but-set-variable for gcc 4.6.0 Fix handling of backlash character in LINUX_COMPILE_BY name kbuild: asm-generic support kbuild: implement several W= levels kbuild: Fix build with binutils <= 2.19 initramfs: Use KBUILD_BUILD_TIMESTAMP for generated entries kbuild: Allow to override LINUX_COMPILE_BY and LINUX_COMPILE_HOST macros kbuild: Drop unused LINUX_COMPILE_TIME and LINUX_COMPILE_DOMAIN macros kbuild: Use the deterministic mode of ar kbuild: Call gzip with -n kbuild: move KALLSYMS_EXTRA_PASS from Kconfig to Makefile Kconfig: improve KALLSYMS_ALL documentation Fix up trivial conflict in Makefile
2011-05-19ftrace/kbuild: Add recordmcount files to force full buildMichal Marek
Modifications to recordmcount must be performed on all object files to stay consistent with what the kernel code may expect. Add the recordmcount files to the main dependencies to make sure any change to them causes a full recompile. Signed-off-by: Michal Marek <mmarek@suse.cz> Link: http://lkml.kernel.org/r/20110517133646.GP13293@sepie.suse.cz Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16kbuild/recordmcount: Add RECORDMCOUNT_WARN to warn about mcount callersSteven Rostedt
When mcount is called in a section that ftrace will not modify it into a nop, we want to warn about this. But not warn about this always. Now if the user builds the kernel with the option RECORDMCOUNT_WARN=1 then the build will warn about mcount callers that are ignored and will just waste execution time. Acked-by: Michal Marek <mmarek@suse.cz> Cc: linux-kbuild@vger.kernel.org Link: http://lkml.kernel.org/r/20110421023738.714956282@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-02kbuild: Allow to combine multiple W= levelsMichal Marek
Add support for make W=12, make W=123 and so on, to enable warnings from multiple W= levels. Normally, make W=<level> does not include warnings from the previous level. Signed-off-by: Michal Marek <mmarek@suse.cz> Acked-by: Sam Ravnborg <sam@ravnborg.org> Reviewed-By: Valdis Kletnieks <valdis.kletnieks@vt.edu>
2011-04-29kbuild: Disable -Wunused-but-set-variable for gcc 4.6.0Dave Jones
Disable the new -Wunused-but-set-variable that was added in gcc 4.6.0 It produces more false positives than useful warnings. This can still be enabled using W=1 Signed-off-by: Dave Jones <davej@redhat.com> Acked-by: Sam Ravnborg <sam@ravnborg.org> Tested-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-04-28kbuild: implement several W= levelsSam Ravnborg
Building a kernel with "make W=1" produces far too much noise to be useful. Divide the warning options in three groups: W=1 - warnings that may be relevant and does not occur too often W=2 - warnings that occur quite often but may still be relevant W=3 - the more obscure warnings, can most likely be ignored When building the whole kernel, those levels produce: W=1 - 4859 warnings W=2 - 1394 warnings W=3 - 86666 warnings respectively. Warnings have been counted with Geert's script at http://www.kernel.org/pub/linux/kernel/people/geert/linux-log/linux-log-summary.pl Many warnings occur from .h files so fixing one file may have a nice effect on the total number of warnings. With these changes I am actually tempted to try W=1 now and then. Previously there was just too much noise. Borislav: - make the W= levels exclusive - move very noisy and making little sense for the kernel warnings to W=3 - drop -Woverlength-strings due to useless warning message - copy explanatory text for the different warning levels to 'make help' - recount warnings per level Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Borislav Petkov <bp@alien8.de> Cc: Dave Jones <davej@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-04-20kbuild: Fix build with binutils <= 2.19Michal Marek
The D option of ar is only available in newer versions. Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-04-18kbuild: Use the deterministic mode of arMichal Marek
Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-03-09kbuild: Add extra gcc checksBorislav Petkov
Add a 'W=1' Makefile switch which adds additional checking per build object. The idea behind this option is targeted at developers who, in the process of writing their code, want to do the occasional make W=1 [target.o] and let gcc do more extensive code checking for them. Then, they could eyeball the output for valid gcc warnings about various bugs/discrepancies which are not reported during the normal build process. For more background information and a use case, read through this thread: http://marc.info/?l=kernel-janitors&m=129802065918147&w=2 Cc: Michal Marek <mmarek@suse.cz> Cc: linux-kbuild@vger.kernel.org Acked-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-11-18ftrace: Speed up recordmcountWu Zhangjin
cmd_record_mcount is used to locate the _mcount symbols in the object files, only the files compiled with -pg has the _mcount symbol, so, it is only needed for such files, but the current cmd_record_mcount is used for all of the object files, so, we need to fix it and speed it up. Since -pg may be removed by the method used in kernel/trace/Makefile: ORIG_CFLAGS := $(KBUILD_CFLAGS) KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS)) Or may be removed by the method used in arch/x86/kernel/Makefile: CFLAGS_REMOVE_file.o = -pg So, we must check the last variable stores the compiling flags, that is c_flags(Please refer to cmd_cc_o_c and rule_cc_o_c defined in scripts/Makefile.build) and since the CFLAGS_REMOVE_file.o is already filtered in _c_flags(Please refer to scripts/Makefile.lib) and _c_flags has less symbols, therefore, we only need to check _c_flags. --------------- Changes from v1: o Don't touch Makefile for CONFIG_FTRACE_MCOUNT_RECORD is enough o Use _c_flags intead of KBUILD_CFLAGS to cover CONFIG_REMOVE_file.o = -pg (feedback from Steven Rostedt <rostedt@goodmis.org>) Acked-by: Michal Marek <mmarek@suse.cz> Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com> LKML-Reference: <3dc8cddf022eb7024f9f2cf857529a15bee8999a.1288196498.git.wuzhangjin@gmail.com> [ changed if [ .. == .. ] to if [ .. = .. ] to handle dash environments ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-21Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (278 commits) arm: remove machine_desc.io_pg_offst and .phys_io arm: use addruart macro to establish debug mappings arm: return both physical and virtual addresses from addruart arm/debug: consolidate addruart macros for CONFIG_DEBUG_ICEDCC ARM: make struct machine_desc definition coherent with its comment eukrea_mbimxsd-baseboard: Pass the correct GPIO to gpio_free cpuimx27: fix compile when ULPI is selected mach-pcm037_eet: fix compile errors Fixing ethernet driver compilation error for i.MX31 ADS board cpuimx51: update board support mx5: add cpuimx51sd module and its baseboard iomux-mx51: fix GPIO_1_xx 's IOMUX configuration imx-esdhc: update devices registration mx51: add resources for SD/MMC on i.MX51 iomux-mx51: fix SD1 and SD2's iomux configuration clock-mx51: rename CLOCK1 to CLOCK_CCGR for better readability clock-mx51: factorize clk_set_parent and clk_get_rate eukrea_mbimxsd: add support for DVI displays cpuimx25 & cpuimx35: fix OTG port registration in host mode i.MX31 and i.MX35 : fix errate TLSbo65953 and ENGcm09472 ...
2010-10-18ftrace: Remove recursion between recordmcount and scripts/mod/emptySteven Rostedt
When DYNAMIC_FTRACE is enabled and we use the C version of recordmcount, all objects are run through the recordmcount program to create a separate section that stores all the callers of mcount. The build process has a special file: scripts/mod/empty.o. This is built from empty.c which is literally an empty file (except for a single comment). This file is used to find information about the target elf format, like endianness and word size. The problem comes up when we need to build recordmcount. The build process requires that empty.o is built first. The build rules for empty.o will try to execute recordmcount on the empty.o file. We get an error that recordmcount does not exist. To avoid this recursion, the build file will skip running recordmcount if the file that it is building is script/mod/empty.o. [ extra comment Suggested-by: Sam Ravnborg <sam@ravnborg.org> ] Reported-by: Ingo Molnar <mingo@elte.hu> Tested-by: Ingo Molnar <mingo@elte.hu> Cc: Michal Marek <mmarek@suse.cz> Cc: linux-kbuild@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-15ftrace: Use objtree for C version of recordmcountSteven Rostedt
The C version of recordmcount is compiled to a binary, which will end up located in the objtree. If the kernel is built with O=path, the srctree will not include the binary recordmcount caller. Cc: Michal Marek <mmarek@suse.cz> Cc: linux-kbuild@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-14ftrace/x86: Add support for C version of recordmcountSteven Rostedt
This patch adds the support for the C version of recordmcount and compile times show ~ 12% improvement. After verifying this works, other archs can add: HAVE_C_MCOUNT_RECORD in its Kconfig and it will use the C version of recordmcount instead of the perl version. Cc: <linux-arch@vger.kernel.org> Cc: Michal Marek <mmarek@suse.cz> Cc: linux-kbuild@vger.kernel.org Cc: John Reiser <jreiser@bitwagon.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-02ARM: 6317/1: ftrace: pass KBUILD_CFLAGS to record_mcount.plRabin Vincent
On ARM, we have two ABIs, and the ABI used is controlled via a config option. Object files built with one ABI can't be merged with object files built with the other ABI. So, record_mcount.pl needs to use the same compiler flags as the kernel when generating the object file with the mcount locations. Ensure this by passing CFLAGS to the script. Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-08-03kbuild: allow assignment to {A,C}FLAGS_KERNEL on the command lineSam Ravnborg
It is now possible to assign options to AS and CC on the command line - which is only used for built-in code. {A,C}FLAGS_KERNEL was used both in the top-level Makefile in the arch makefiles, thus users had no way to specify additional options to AS, CC without overriding the original value. Introduce a new set of variables KBUILD_{A,C}FLAGS_KERNEL that is used by arch specific files and free up {A,C}FLAGS_KERNEL so they can be assigned on the command line. All arch Makefiles that used the old variables has been updated. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-08-03kbuild: allow assignment to {A,C,LD}FLAGS_MODULE on the command lineSam Ravnborg
It is now possible to assign options to AS, CC and LD on the command line - which is only used when building modules. {A,C,LD}FLAGS_MODULE was all used both in the top-level Makefile in the arch makefiles, thus users had no way to specify additional options to AS, CC, LD when building modules without overriding the original value. Introduce a new set of variables KBUILD_{A,C,LD}FLAGS_MODULE that is used by arch specific files and free up {A,C,LD}FLAGS_MODULE so they can be assigned on the command line. All arch Makefiles that used the old variables has been updated. Note: Previously we had a MODFLAGS variable for both AS and CC. But in favour of consistency this was dropped. So in some cases arch Makefile has one assignmnet replaced by two assignmnets. Note2: MODFLAGS was not documented and is dropped without any notice. I do not expect much/any breakage from this. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Acked-by: Mike Frysinger <vapier@gentoo.org> [blackfin] Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> [avr32] Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-06-04Makefile.build: make KBUILD_SYMTYPES work againDon Zickus
commit 37a8d9f67f18de1e2cbc7387311ce22d4dbff518 tried to combine some duplicate code and accidentally broke how KBUILD_SYMTYPES worked This fixes the code to match the original intention by the author who originally added the code I believe. The fixes include: - removing extra whitespaces in the if-statements - moving the if-statement from around the -r to the -T - adding a second arg to cmd_gensymtypes to simplify the options passed to genksyms. Tested by instrumenting genksyms and seeing what options were passed in during a make, KBUILD_SYMTYPES make, and when a foo.symref was created. Everything compiled and looked ok. Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Michal Marek <mmarek@suse.cz>